Sorry but it will not change significantly your performance as WoT is using only one Core of the processor. It will limit access to your graphic processor and memory anyway. So If you are planning to buy computer for WoT - make sure that single Core is as big as possible or you can just buy computer as described and wait for new game engine. If they will access 3 other cores - you will have really good gaming machine.

You have chosen a budget GFX card, I recommend you to move up to mid range cards. It doesn't look like Nvidia has got any good mid range cards for the 600 series at the moment. AMD has though. 77xx-78xx should suit your needs best.

To sum it up, swap your budget GFX card with a midrange one and you'll have an excellent system for not so much money.

DDR3 is the third version of DDR(not East Germany, for you witty guys). It should also be noted that it is the amount of RAM that makes the biggest difference. Higher clock speed or lower access times should not be a concern unless you are benchmarking.

edit: the "k" prefix in Intel's CPUs are more expensive and offer no performance gain over the non "k" models other than the overclocking aspect